[PATCH 08/10] diff.c: factor advance_or_nullify out of mark_color_as_moved

[Stefan Beller]

This moves the part of code that checks if we're still in a block
into its own function.  We'll need a different approach on advancing
the blocks in a later patch, so having it as a separate function will
prove useful.

While at it rename the variable `p` to `prev` to indicate that it refers
to the previous line. This is as pmb[i] was assigned in the last iteration
of the outmost for loop.

Further rename `pnext` to `cur` to indicate that this should match up with
the current line of the outmost for loop.

Also replace the advancement of pmb[i] to reuse `cur` instead of
using `p->next` (which is how the name for pnext could be explained.

Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Junio C Hamano <gits...@pobox.com>
---
 diff.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/diff.c b/diff.c
index 70eeb40c5fd..4963819e530 100644
--- a/diff.c
+++ b/diff.c
@@ -801,6 +801,25 @@ static void add_lines_to_move_detection(struct 
diff_options *o,
        }
 }
 
+static void pmb_advance_or_null(struct diff_options *o,
+                               struct moved_entry *match,
+                               struct hashmap *hm,
+                               struct moved_entry **pmb,
+                               int pmb_nr)
+{
+       int i;
+       for (i = 0; i < pmb_nr; i++) {
+               struct moved_entry *prev = pmb[i];
+               struct moved_entry *cur = (prev && prev->next_line) ?
+                               prev->next_line : NULL;
+               if (cur && !hm->cmpfn(o, cur, match, NULL)) {
+                       pmb[i] = cur;
+               } else {
+                       pmb[i] = NULL;
+               }
+       }
+}
+
 static int shrink_potential_moved_blocks(struct moved_entry **pmb,
                                         int pmb_nr)
 {
@@ -875,7 +894,6 @@ static void mark_color_as_moved(struct diff_options *o,
                struct moved_entry *key;
                struct moved_entry *match = NULL;
                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-               int i;
 
                switch (l->s) {
                case DIFF_SYMBOL_PLUS:
@@ -906,17 +924,7 @@ static void mark_color_as_moved(struct diff_options *o,
                if (o->color_moved == COLOR_MOVED_PLAIN)
                        continue;
 
-               /* Check any potential block runs, advance each or nullify */
-               for (i = 0; i < pmb_nr; i++) {
-                       struct moved_entry *p = pmb[i];
-                       struct moved_entry *pnext = (p && p->next_line) ?
-                                       p->next_line : NULL;
-                       if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
-                               pmb[i] = p->next_line;
-                       } else {
-                               pmb[i] = NULL;
-                       }
-               }
+               pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 
                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
-- 
2.18.0.233.g985f88cf7e-goog